This invention concerns mechanical devices for transferring mechanical power from components with reciprocating motion to components with rotary motion.
In U.S. Pat. No. 3,955,432, issued May 11, 1976, there is disclosed a transmission having a first element defining a pair of rolling surfaces of revolution about a first axis, a second element having a pair of rolling surfaces of revolution on a second axis intersecting the first axis and including a system for urging the rolling surfaces of the second element against those of the first element, which system is gyroscopic in origin. Specifically, inertial means associated with the second element are deployed to develop a gyroscopic couple which acts to retain the rolling surfaces of the second element against the rolling surfaces of the first element at two points of contact located one on each side of a plane perpendicular to the first axis at the point of intersection thereof with the second axis. The gyroscopic couple thus developed is a combined function of the moment of inertia of the second element with respect to the second axis, the angle at which the first and second axes intersect, the rotational velocities of the second element around the first axis. In this transmission, the gyroscopic couple operates to both rock the second element around the point of axes intersection and maintain both rolling surfaces of the second element against both such surfaces of the first element in rolling friction contact.
To vary the ratio of input and output speeds of the transmission disclosed in this patent, provision is made to modify the angle of inclination of the second axis with respect to the first axis. As a result, the ratio of the radii of circles described by the points of rolling surface contact between the first and second elements, respectively, will be modified. Such a transmission is particularly well suited for the transmission of large forces due to the development of normal contact pressure by the gyroscopic couple while avoiding excessive axial forces on the transmission gear shafts as well as radial forces on the bearing supporting the second element.
Also in a corresponding U.S. application for patent Ser. No. 706,291, filed July 19, 1976 and owned in common with the present invention, the basic principles underlying the transmission disclosed in the afore-mentioned U.S. patent are again used but in an arrangement having an increased range of speed ratio variation without the requirement for variation in the angle of intersection between the axes of the respective first and second elements. This characteristic of operation is achieved by providing on one of the elements a pair of oppositely convergent cone-like rolling surfaces in which the apical half-angle of surface convergence (or divergence) is approximately equal to the angle at which the axes of the two elements intersect one another. The other of the two elements is provided with ring-like tracks providing the rolling surfaces so that the speed ratio of the transmission may be variable with the ratio of the rolling surface radii on the ring-like tracks to the radii of the cone-like members at the two points of rolling contact between the two elements.